Construction of the Tenth Street Rail Corridor in Springfield has officially begun after a ceremonial groundbreaking Thursday. Over the projected two years of construction, an underpass will be built at Tenth and Carpenter for vehicles and pedestrians, allowing trains to pass above.

"When somebody has a medical emergency, time is of the essence," he said.

The underpass at Tenth and Carpenter is the first phase of the long-term corridor project, which aims to convert all intersections along Tenth Street into underpasses. Eventually, trains that run along Third Street would be shifted to Tenth under the plan.

A federal grant is bolstering much of this first stage, which totals $20 million for engineering, land acquisition and construction.